Prediction of Remediation Rates of Microbes in Polluted Crude Oil Soil Samples

B C Okoro,J C Agunwamba,O A Nwadike

doi:10.5539/enrr.v3n3p89

Abstract

The rate of removal of Total Petroleum Hydrocarbon Content (TPHC) of a crude oil polluted land was investigated using field experimental data generated from the Research Farm soil at the Federal University of Technology Owerri, Imo State, Nigeria. The soil was artificially polluted in the laboratory with crude oil - bonny light - with specific gravity of 0.8323. Petroleum contaminant present in the soil was 230 mg per kilogram of soil. The treatment variables used include: inorganic fertilizer (NPK 20:10:10), poultry manure, cow dung and a mixture of the three in equal proportion. A natural treatment was allowed to occur as the control experiment. fungi as well as bacteria played an important role in the degradation of petroleum hydrocarbon. The identified crude oil degrading Fungi are Penicillium notatum, Mucor spp, Rhizopus stolonifer and Penicillum caseicolum with P. notatum and P. caseicolum (penicillum spp) as the strongest fungi degraders. The identified degrading Bacteria are Pseudomonas putida and Bacillus subtilis. These can therefore be isolated and cultured and then employed on remediation sites either as indigenous or foreign degrading microbes in the engineering of bioremediation of crude oil polluted soil using the best engineering techniques. The treatment with mixture of treatment variables proved to be a better option from the results obtained with 82.38 mg/kg after 9 weeks of remediation followed by fertilizer, 83.13 mg/kg and 86.75 mg/kg for poultry manure. Cow dung had 105.5 mg/kg and the control had least with 204.50 mg/kg.

Highlights

There is a growing concern over environmental pollution and it’s management
A natural treatment was allowed to occur as the control experiment. fungi as well as bacteria played an important role in the degradation of petroleum hydrocarbon
The sharp increase in the microbial load of hydrocarbon degrading fungi and bacteria within the 6th and 9th weeks resulted in sharp reduction in Total Petroleum Hydrocarbon Content (TPHC) which is seen in the increase in the % reduction

Summary

Introduction

There is a growing concern over environmental pollution and it’s management. The three major areas of environmental pollution include: water, air and land. One of the major causes of this environmental pollution in Nigeria is as a result of hydrocarbon exploitation and exploration (Okwuosha, 2000). This has led to the degradation of farmlands, pollution of surface and ground waters as well as air due to gas flaring. Remediation has been defined as “the management of a contaminant at a site so as to prevent, reduce or mitigate damage to human health or the environment which can lead to quick recovery of the affected land” (Dodman, 1994; Ebuehi et al, 2005)

Methods

Results

Discussion

Conclusion